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Biomedical subjects

D Duff

Publications and source records attributed to D Duff.

18 recordsLinked to original sources
PubMed2006

Differential DNA methylation patterns of small B-cell lymphoma subclasses with different clinical behavior.

Non-Hodgkin's lymphoma (NHL) is a group of malignancies of the immune system with variable clinical behaviors and diverse molecular features. Despite the progress made in classification of NHLs based on classical methods, molecular classifications are a work in progress. Toward this goal, we used an array-based technique called differential methylation hybridization (DMH) to study small B-cell lymphoma (SBCL) subtypes. A total of 43 genomic DMH experiments were performed. From these results, several statistical methods were used to generate a set of differentially methylated genes for further validation. Methylation of LHX2, POU3F3, HOXC10, NRP2, PRKCE, RAMP, MLLT2, NKX6.1, LRP1B and ARF4 was validated in cell lines and patient samples and demonstrated subtype-related preferential methylation patterns. For LHX2 and LRP1B, bisulfite sequencing, real-time reverse transcriptase-polymerase chain reaction and induction of gene expression following treatment with the demethylating agent, 5'-aza-2'-deoxycytidine, were confirmed. This new epigenetic information is helping to define molecular portraits of distinct subtypes of SBCL that are not recognized by current classification systems and provides valuable potential insights into the biology of these tumors.

Adult↗
PubMed2005

Guidelines for the medical management of Irish children and adolescents with Down syndrome.

Down syndrome (DS) is the most common chromosomal cause of developmental disability in Ireland. Children with DS have a high incidence of associated treatable medical disorders where early intervention carries a better outcome. Currently there are no agreed protocols for the screening and management of children and adults with DS in Ireland. A cross-sectional study of 394 children and adolescents was undertaken in the Eastern Regional Health Authority (ERHA) to assess the medical needs of children and adolescents with DS, in order to develop medical management guidelines. This study provides evidence-based data that children and adolescents with DS have a high incidence of treatable medical disorders, which supports the need for the medical management guidelines presented.

Adolescent↗
PubMed2001

Review article: altered states of consciousness, theories of recovery, and assessment following a severe traumatic brain injury.

The causes and consequences of severe traumatic brain injury are reviewed, including mechanical injury and neurochemical changes following focal and diffuse injuries. A discussion of terminology seeks to clarify current nomenclature and descriptions of behaviours during emergence from coma. Theories of recovery following severe brain injury are reviewed including diaschisis, plasticity and compensation, redundancy, environmental regulation, and excess disability. Several assessment tools that have been recommended for use with this population of individuals in an altered state of consciousness following coma are discussed and critiqued. They include the Glasgow Coma Scale, Ranchos Los Amigos Levels of Cognitive Functioning Assessment Scale, Western Neuro Sensory Stimulation Profile, Coma Near Coma Scale, Freeman Questionnaire, and the Sensory Modality Assessment Rehabilitation Technique.

Brain Injuries↗
PubMed2001

Writing for publication.

A discussion of the benefits and obstacles of authoring a paper for a nursing journal is followed by an explanation of the process of writing for publication. Benefits include advancing nursing knowledge and professional recognition of the individual author. The barriers addressed are time, failure to recognize expertise, a reluctance to subject one's work and ideas to the public arena for scrutiny, and lack of confidence with scholarly writing. The discussion focuses on choosing a suitable journal and subject, the role of the editor and peer reviewers in a refereed journal, and a procedure for planning, writing, and editing a paper. The process is addressed both in a generic sense, and specifically when writing a paper for AXON. Strategies to get nurses started with writing, such as critical reading of journal articles individually or with a peer group, writing with a mentor or group, and starting with small projects, are also included.

Authorship↗
PubMed2000

Directiveness in teachers' language input to toddlers and preschoolers in day care.

Five subtypes of directiveness were examined in the interactions of day care teachers with toddler and preschooler groups. The instructional context (book reading, play dough) yielded significant differences across all five subtypes of directiveness, indicating that these two activities elicited different types of teacher-child discourse. Book reading was characterized by significantly more behavior and response control and less conversation control in comparison with the play-dough activity. Correlations between teachers' directiveness and child language productivity indicated that behavior control and turn-taking control were associated with low levels of productivity, whereas conversation control was associated with the highest levels of productivity. The results of this study confirm that instructional context is an important mediator of teachers' directiveness and suggest that subtypes of directiveness have differential effects on child language output.

Child Day Care Centers↗
PubMed1999

Striae and acne following cardiac surgery in a child.

We report a 13-year-old girl with extensive striae and an acneiform eruption following surgery for complex congenital heart disease. These findings were associated with elevated serum and urinary cortisol levels with loss of diurnal rhythm. The resolution of the eruption and the fading of her striae coincided in time with normalization of her blood parameters on day 72 postoperatively. We conclude that the cause of steroid excess in our patient was stress induced by the cardiac surgery and a complicated and protracted postoperative course. To our knowledge, this is the first report in the English language literature of skin changes due to endogenous hypercortisolaemia caused by intense physical and emotional stress.

Acne Vulgaris↗
PubMed1998

New mutations in the KVLQT1 potassium channel that cause long-QT syndrome.

BACKGROUND: Long-QT syndrome (LQTS) is an inherited cardiac arrhythmia that causes sudden death in young, otherwise healthy people. Four genes for LQTS have been mapped to chromosome 11p15.5 (LQT1), 7q35-36 (LQT2), 3p21-24 (LQT3), and 4q25-27 (LQT4). Genes responsible for LQT1, LQT2, and LQT3 have been identified as cardiac potassium channel genes (KVLQT1, HERG) and the cardiac sodium channel gene (SCN5A). METHODS AND RESULTS: After studying 115 families with LQTS, we used single-strand conformation polymorphism (SSCP) and DNA sequence analysis to identify mutations in the cardiac potassium channel gene, KVLQT1. Affected members of seven LQTS families were found to have new, previously unidentified mutations, including two identical missense mutations, four identical splicing mutations, and one 3-bp deletion. An identical splicing mutation was identified in affected members of four unrelated families (one Italian, one Irish, and two American), leading to an alternatively spliced form of KVLQT1. The 3-bp deletion arose de novo and occurs at an exon-intron boundary. This results in a single base deletion in the KVLQT1 cDNA sequence and alters splicing, leading to the truncation of KVLQT1 protein. CONCLUSIONS: We have identified LQTS-causing mutations of KVLQT1 in seven families. Five KVLQT1 mutations cause the truncation of KVLQT1 protein. These data further confirm that KVLQT1 mutations cause LQTS. The location and character of these mutations expand the types of mutation, confirm a mutational hot spot, and suggest that they act through a loss-of-function mechanism or a dominant-negative mechanism.

Case-Control Studies↗
PubMed1998

The vocal athlete and endotracheal intubation: a management protocol.

Endotracheal intubation is associated with significant laryngeal sequelae that range in severity from mild hoarseness to life-threatening tracheal stenosis. Although the most severe trauma appears to be related to prolonged intubation, even short-term intubation (< 1 day) can adversely affect laryngeal and vocal function. Concern is warranted for all intubated patients, but particularly for the vocal athlete whose livelihood and identity depend on optimal vocal function. It is proposed that the vocal athlete faced with endotracheal intubation risk warrants careful multidisciplinary management. A number of intubation risk factors have been identified in the literature; however, clinical management of vocal athletes who undergo intubation has not been addressed. In medical settings where adverse intubation outcomes can lead to litigation, this clinical management protocol is expected to improve the probability of favorable voice outcome following endotracheal intubation.

Counseling↗
PubMed1998

Tissue and whole-body extracellular, red blood cell and albumin spaces in the rainbow trout as a function of time: a reappraisal of the volume of the secondary circulation

[58Co]EDTA, [51Cr]RBC and [125I]albumin spaces in the whole body and 28 tissue samples were examined at timed intervals over 16 h in rainbow trout Oncorhynchus mykiss. [58Co]EDTA space (which approximates extracellular fluid volume; ECF) in fins, skin, gallbladder and eye are reported for the first time. After a 16 h equilibration, ECF volume was large (376-726 microl g-1 wet tissue mass) in kidney, swimbladder, skin and fins, moderate (219-313 microl g-1 wet tissue mass) in stomach, skull, spleen, liver, intestine, gills, eye and cecum, and small (53-181 microl g-1 wet tissue mass) in red muscle, fat, brain, gallbladder and white muscle. Whole-body ECF was 387+/-10.6 microl g-1 (mean +/- s.e.m.; N=11). [51Cr]RBC space relative to [58Co]EDTA space was large in spleen, liver, intestine and gill, and low in skin, fins, stomach and skull. Whole-body [51Cr]RBC space was 9.9+/-0.6 microl g-1 body mass (N=17). Blood volume calculated from [51Cr]RBC space at 16 h and a dorsal aortic hematocrit of 24.5 % was 40.4 microl g-1 body mass. Whole-body [125I]albumin space at 16 h was 118.0+/-7.4 microl g-1 body mass (N=6), which resulted in an estimated blood volume of 156. 6 microl g-1 body mass, nearly four times that estimated from the [51Cr]RBC space. Tissue hematocrits, calculated from [125I]albumin and [51Cr]RBC spaces, were significantly lower than dorsal aortic hematocrit in all tissues except spleen, kidney and liver. [58Co]EDTA and [51Cr]RBC spaces reached equilibrium in nearly all tissues within 1 h, whereas [125I]albumin continued to accumulate in many tissues up 24 h. The disparity between [125I]albumin distribution kinetics compared with the kinetics of [58Co]EDTA and [51Cr]RBC distribution, as well as the accumulation of [125I]albumin in tissues not known to have a secondary circulation, indicates that [125I]albumin is a poor marker of plasma volume in trout and that previous studies based on [125I]albumin clearance from the plasma have overestimated both the volume and the turnover rate of the secondary system. Revised estimates of secondary circulation volume, based on [58Co]EDTA distribution rate, indicate that it is no more than 10-20 % of the volume of the primary circulation.

Journal Article↗
PubMed1993

10 year review of cardiac tumours in childhood.

OBJECTIVE: To review the commonest types of cardiac tumours in childhood, their different presentations, and management. DESIGN: A retrospective study of patients with cardiac tumours. SETTING: Cardiac department of a teaching hospital. PATIENTS: Six patients with an age range between one day to three years presented over a period of 10 years. MAIN OUTCOME MEASURES: To determine different presentations, management, and prognosis of cardiac tumours. RESULTS: Three patients presented with an arrhythmia, two with an asymptomatic heart murmur, and the sixth was discovered accidentally. Surgical resection of the tumours was performed in five cases, one patient died during the operation, one developed new tumours after surgery, and the remaining three have had an excellent result. Histology of those operated on showed benign rhabdomyomas in three and fibromas in the other two. The sixth patient was managed conservatively and the multiple tumours he had showed gradual resolution over a period of 10 months follow up. One baby with rhabdomyoma had signs of tuberous sclerosis whereas the others were normal at follow up five months to three years after diagnosis. None of them had a positive family history. CONCLUSION: Cardiac tumours in childhood are extremely rare. The commonest types are rhabdomyomas, then fibromas. Most cases are diagnosed by echocardiography. The prognosis for most patients is excellent.

Child, Preschool↗
PubMed1987

The effect of hypophysectomy on chloride balance in young-of-the-year bowfin, Amia calva.

The effect of hypophysectomy on chloride balance was examined in young-of-the-year bowfin, Amia calva. Hypophysectomy resulted in decreased serum and total body chloride levels but not in serum and total body sodium levels. Hypophysectomy resulted in decreased chloride influx with no effect on chloride efflux or sodium fluxes. Prolactin therapy reversed the effect of hypophysectomy on electrolyte balance but caused a significant reduction in serum protein.

Animals↗
PubMedDate not supplied

Antimicrobial prophylaxis in children with urinary tract infection and vesicoureteral reflux.

Thirty children with urinary tract infection and nonobstructive vesicoureteral reflux have been followed prospectively for a mean of 17 months. After classification according to age and grade of reflux, 10 patients were assigned at random to treatment with antimicrobial prophylaxis alone or antimicrobial prophylaxis plus corrective surgery. Twenty other patients were also treated with antimicrobial prophylaxis alone. All were assigned at random to treatment with a single daily dose of trimethoprim-sulfamethoxazole or nitrofurantoin. Cultures of urine, complete blood cell counts, and determination of levels of aspartate aminotransferase in serum were performed regularly during follow-up. Both drugs proved effective in prevention of recurrent infection, and no significant hematologic or hepatic abnormalities were noted. Current results suggest that either prophylaxis or surgery may effectively prevent chronic pyelonephritis or reflux nephropathy, but only continuing evaluation of this group of patients will confirm these results.

Child↗
PubMedDate not supplied

Reversible pulmonary hypertension in neonatal Graves disease.

Neonatal thyrotoxicosis may occur by transplacental transfer of thyroid stimulating immunoglobins from the mother. Although the clinical manifestations may vary in the new-born period, hyperthyroidism has been associated with several cardiac complications including supraventricular tachycardia, cardiomyopathy and congestive cardiac failure. We report the case of a nine day old baby who presented with severe pulmonary hypertension in association with congestive cardiac failure secondary to neonatal thyrotoxicosis. Treatment of the heart failure and restoration of the thyroid function resulted in complete regression of the pulmonary hypertension. The recognition and reversibility of pulmonary hypertension in neonatal Graves disease has not been previously described.

Antithyroid Agents↗